The D'Entrecasteaux Channel scallop fishery : its past, present and future

The past and present structure and management of the D'Entrecasteaux Channel scallop fishery is examined with a view to providing a basis for the future management of the fishery. The fishery has suffered mixed fortunes since its beginnings in the early 1920's. Production has fluctuated markedly over the years, reaching a peak in 1961, and subsequently collapsing. The fishery was closed from 1970 - 1981, re-opened from 1982 - 1985, but closed again in 1986. The causes of the fluctuations in scallop production, and its collapse in the 1960's, .include changes in fishing technology, excessive fishing effort and the inherent variability in the annual recruitment of scallops. The 1986 closure was forced by evidence of over-fishing, and the sudden appearance of the toxic dinoflagellate alga Gymnodinium catenatum Graham in the Channel area. There is a lack of a comprehensive management plan for the D'Entrecasteaux Channel scallop fishery, and this is a serious obstacle to the successful conservation and utilization of the resource, as many of the administrative and biological problems, such as excessive fishing effort and the variable spatfall of scallops, are difficult to overcome. Moreover, there have been unexpected developments since the re-opening of the fishery in 1982: a great many more amateur fishermen now participate in the fishery, and the doughboy scallop (Chlamys asperrimus Lamarck) is now more numerous than the commercial scallop (Pecten fumata Tate). Theoretical and practical management techniques applied in other fisheries are examined and assessed. Because of its flexible nature, the concept of Optimum Sustainable Yield appears most suitable for the Channel fishery, and practical management should continue to include catch quotas, gear limitations, area closures, seasons, and size limits, as they provide a degree of control over fishing effort. Specific recommendations made are that the Channel scallop fishery should be amateur-only while scallop stocks remain low, that the level of enforcement and fines for breaches of fisheries regulations should be increased, and that research on scallops in the Channel, particularly the doughboy scallop, should be upgraded.